Pthpool

Pthpool is a lightweight, POSIX compliant thread pool implementation that aims to achieve a balance between useful functionality and simple API.

• Easy integration with existing code using pthread
• Timed wait for asynchronous execution result
• Flexible to cancel pending tasks

Usage

Below is a typical workflow when using Pthpool. Refer to the API section for more detailed documentation.

1. Include the header file: #include "pthpool.h"
2. Create a thread pool with desired number of threads: pthpool_t pool = pthpool_create(NUM_OF_THREADS);
3. Submit tasks to the thread pool: pthpool_future_t future = pthpool_apply(pool, task, (void *)arg);
4. Wait for arbitrary seconds to get the result of execution: void *result = pthpool_future_get(future, seconds);
5. Destroy the future object once it's no longer used: pthpool_future_destroy(future);
6. Wait for all pending tasks to complete and destroy the thread pool: pthpool_join(pool);
7. Compile the source files with pthpool.c and option -pthread

API

pthpool_t pthpool_create(size_t count)

Create a thread pool containing specified number of threads. If successful, the thread pool is returned. Otherwise, pthpool_create() returns NULL.

**pthpool_future_t pthpool_apply(pthpool_t pool, void *(*func)(void ), void arg)

Schedules the function func to be executed as func(arg). If successful, a future object representing the execution of the task is returned. Otherwise, pthpool_apply() returns NULL.

int pthpool_join(pthpool_t pool)

Wait for all pending tasks to complete before destroying the thread pool.

int pthpool_terminate(pthpool_t pool)

Cancel all pending tasks and destroy the thread pool.

*void pthpool_future_get(pthpool_future_t future, unsigned int seconds)

Return the result when it becomes available. If seconds is non-zero and the result does not arrive within specified time, NULL is returned. Each pthpool_future_get() resets the timeout status on future.

int pthpool_future_cancel(pthpool_future_t future)

Attempt to cancel the task execution. If the function is either running or finished, cancellation fails and returns -1. If successful, 0 is returned.

int pthpool_future_destroy(pthpool_future_t future)

Destroy the future object and free resources once it's no longer used. It's an error to refer to a destroyed future object. Note that destroying a future object does not prevent a pending task from being executed.

int pthpool_future_finished(pthpool_future_t future)

Return 1 if the task completes execution, 0 otherwise.

int pthpool_future_timeout(pthpool_future_t future)

Return 1 if the last pthpool_future_get() on future results in a timeout, 0 otherwise.